Note pads comprising a stack of sheets adhesively secured along one edge are by now well known, and include the Note Stix.RTM. brand pads manufactured and sold by the assignee of this invention. The self-stick adhesive strips applied to the underside of the sheets in such pads permits one sheet to be peeled from the next, and the separated sheet may then be re-adhered to another surface. This adhesive is also well known, and is often referred to as "low tack" or "repositionable" adhesive. As will be appreciated, the advent of such note pads has given rise to a variety of pad constructions for use in many fields. One relatively new application relates to a label pad in which individual label sheets are provided with low tack or repositionable adhesive along two opposite edges of each label sheet within the pad. This type of pad is used, for example, by product manufacturers who remove the labels, one at a time, from the pad and then adhere them to finished products (for example, prefabricated window assemblies) prior to shipment. A problem exists in that it is often difficult to locate an edge (or portion of an edge) of the label sheet which will most easily permit removal of the sheet from the pad. If, for example, one were to attempt to peel the label from the pad along one of the two edges extending perpendicular to the opposite adhesive edges, the label sheet will often tear. Moreover, upon peeling the label sheet from the pad, edge curling often occurs. Because of the low tack nature of the adhesive, the one or more curled edges tend to override the sticking power of the adhesive so that the label edges curl away from the product to which the label is ultimately adhered. In a case of severe curling, the label sheet may completely separate from the product.
It is the principal object of this invention to provide a simple mechanical device which will quickly and reliably separate an uppermost label sheet from a pad of such sheets, without tearing and without incurring curled edges. In other words, the label sheet as separated from the stack in accordance with this invention remains in a substantially flat condition so that it may be reliably adhered to a product or other "end use" surface.
In an exemplary embodiment, the device of this invention includes a housing supporting a pad of label sheets, urging the pad or stack upwardly to a reference position where the uppermost label sheet may be removed as described herein. The housing mounts a sheet separator mechanism for manually driven reciprocating movement in opposite horizontal directions relative to the housing and to the stack.
The sheet separator includes geared drive wheels movable along laterally spaced gear tracks which confine the sheet separator to straight-line (or axial) reciprocating movements, i.e., in a forward direction to separate the uppermost sheet and in a rearward direction to re-set the separator mechanism. In the exemplary embodiment, the pad is oriented so that adhesive edges of the label sheets lie along the gear tracks, i.e., parallel to the direction of movement of the sheet separator. The separator mechanism includes a substantially planar blade member which acts in concert with a "pick wheel" which, in turn, is arranged to initially lift the uppermost label sheet slightly, at an intermediate, localized area along a transverse edge of the label sheet. Immediately upon lifting of the localized edge portion, and as the separator mechanism continues to be driven in the separating direction, the separator blade will move through the pad, beneath the uppermost sheet. As the blade progresses through the pad, the uppermost sheet is progressively separated along the two opposite adhesive edges. Upon completion of the forward stroke of the separator mechanism, the uppermost label sheet is simply lifted off the separator mechanism in a flat condition, and is re-adhered to another surface as desired. The separator mechanism is then returned and re-set for separation of the next uppermost label sheet.
The pick wheel is caused to rotate by means of a gear train connected to the geared drive wheels. The gear connection is such that the pick wheel rotates in a direction opposite to that of the drive wheels. Both the pick wheel and the blade are secured to the sheet separator mechanism in substantially fixed axial relationship to each other.
Thus, in accordance with its broader aspects, the invention provides for use with a pad of sheets where each sheet is adhered to an underlying sheet by a pair of laterally spaced, substantially parallel strips of light tack adhesive located along opposite side edges of the sheet, a device for separating an uppermost sheet of the pad comprising lifting means for lifting an edge of the uppermost sheet intermediate the parallel strips of light tack adhesive; blade means for insertion between the uppermost sheet and an underlying sheet at a location where the transverse edge has been lifted by the lifting means; and drive means for moving the blade means in a first direction parallel to the strips of light tack adhesive through the pad to thereby separate the uppermost sheet from the underlying sheet.
In another aspect, the invention relates to a sheet separating device for removing an uppermost sheet of an adhesive pad containing a plurality of such sheets, the device comprising a housing; a support plate for holding said pad, said support plate being resiliently biased in an upward direction; a sheet separator mechanism movable in forward and rearward directions, the sheet separator mechanism including a frame, a pick wheel mounted for rotation within the frame, and a knife blade having a closed periphery opening therein defined in part by at least one entry projection, wherein the pick wheel is located ahead of the at least one entry projection of the knife blade in the forward direction such that, in use, the pick wheel lifts an edge of the upper most sheet extending transverse to the forward direction, and the at least one entry projection of the knife blade then moves between the uppermost sheet and a next underlying sheet.
It will be appreciated that the apparatus described herein is highly advantageous in any circumstance where it is desired to successively remove sheets from an adhesive pad without tearing the sheet and/or curling the edges of the separated sheet. Other objects and advantages will become apparent from the detailed description which follows.